Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
The paradigm shift from on-premises computing, to cloud computing supported by an external provider, reduces costs to end users through externalization of storage, infrastructure, and database management. Along with these benefits, however, cloud computing also raises novel confidentiality risks for data outsourced to the external provider.
Specifically, by outsourcing sensitive data, the user is required to place trust in the service provider. While this security can be further enforced using cryptographic measures that prevent unauthorized attempts, such protection can interfere with or preclude entirely, the desirable manipulation of the stored data for analysis purposes.
For example, despite providing semantic security for the outsourced data, the application of common cryptographic techniques may render normal database computations (such as join operations) difficult or impossible to perform.